Telephone lock



March 4, 1952 STRAUCH 2,588,176

TELEPHONE LOCK Filed 001;. 6, 1950 I'VV I INVENTOR JOHN STRAUCH QMZM. Ah

ATTORNE Patented Mar. 4, 1952 UNITED STATES rATENr OFFICE TELEPHONE LooK John Strauch, Philadelphia, Pa.

Application October 6, 1950, Serial No. 188,900

3 Claims.

The present invention relates to locking devices for telephones and it relates more particularly to a locking device for a French-type telephone.

An object of the present invention is to provide a new and improved locking device for a telephone. Another object of the present invention is to provide a novel lock for a French-type dial telephone which will not only prevent use of the dial for the making of outside calls but also prevent lifting of the receiver-transmitter unit or handset from the base for listening in on extension lines.

Other objects and advantages of the present invention are apparent in the following detailed description, appended claims and accompanying drawings.

Various locking devices have heretofore been suggested for preventing unauthorized use of telephones. However, none of these conventional devices heretofore employed has been capable of use on a handset or French-type telephone, that is a telephone having a combination transmitterand-receiver with an earphone and a mouthpiece supported on a base, equipped with a dial.

According to the present invention there has been developed, for the first time, a simple, inexpensive and effective lock for a French-type dial telephone, which will prevent use of the dial for the making of unauthorized outside calls and will also secure the receiver-transmitter unit or handset to the base to prevent unauthorized listening in on extension lines.

For the purpose of illustrating the invention,

one form thereof, which is presently preferred,

is shown and described herein, although it is to be understood that the invention is not limited to the precise arrangements and instrumentalities disclosed.

Referring to the accompanying drawings, in which like reference characters indicate like parts throughout:

Figure 1 represents a perspective view of one embodiment of the present invention.

Figure 2 represents a front perspective view of the embodiment of Figure 1 as it appears when installed on a French-type dial telephone.

Figure 3 represents an elevational view, looking from the rear of Figure 2.

Figure 4 represents a fragmentary vertical cross-sectional view, on an enlarged scale, generally along the line 4-4 of Figure 2.

As shown particularly in Figure 1, the novel telephone locking device of the present invention includes a generally cylindrical lock I having a boss II formed at its inner end and having a locking-cam or eccentric I2 mounted on a shaft I3 in juxtaposition to the'b'oss II. In-its open position shown in solid lines in Figure l, the"lo'ck ing-cam I2 generally coincides with the boss- II. In its locking position shown-in dash-dot lines in Figure l (and also shown in solid linesin Figure 4), the locking-cam I 2 is laterally displaced from the boss I I. A shoulder I4 extends inwardly from the lock ID, in radially-spaced relationship therewith.

The front-arm I5 of a clamp (formed of relatively thinfiat form-retaining sheetemetalor the like) is fastened to the lock I0 as at I6 (for example, by welding or soldering or any other suitable manner) and extends upwardly therefrom, merging into the integrally-formed reararm IT. The clamp is generally V-shaped; that is, its front-arm I5 forms an acute angle with its rear-arm I1. The lower end of the rear-arm I1 is provided with an inwardly-directed engaging-lip I8.

As indicated in Figures 2-4, the base I9 of a French-type telephone includes an undercut shelf or ledge 20 extendin transversely intermediate the receiver-rests 2I; the rear free edge 22 of the shelf 2i! having an enlarged bead 23 formed on its underside.

The locking device of the present invention is installed by fitting the engaging-lip I8 beneath the bead 23 and bringing the V-shaped clamp into the position shown in Figures 2-4 wherein it overlies the receiver-transmitter unitor handset 24 of the telephone with the lock I0 adjacent the top of the dial 25.

The lock I0 is then forced against the dial (the V-shaped clamp preferably being slightly resilient so that there is a little give) until the boss II and the locking-cam I2 (which is in the open position shown in dash-dot lines in Figure 4) enter one of the finger-openings 26 of the dial 25. The key is then inserted into look I 0 and turned to move the locking-cam IZ to the elf-center locking position shown in solid lines in Figure 4 wherein it underlies the dial 25. With the shoulder I4 extending beyond the outer edge of the dial, it is apparent that the lock is thus anchored to the dial so as to prevent rotation of the latter and, at the same time, to secure the clamp in overlying relationship to the unit or handset 24 and to prevent the unit or handset from being lifted from the base.

It is apparent, therefore, that the, telephone is locked both against unauthorized use of the telephone for outside calls as well as against unde sired listening in on extensions.

When the lock is opened with the key, the locking-cam is rotated back to its centered position shown in dash-dot lines in Figure 4 so that the lock can be disengaged from the dial 25 and the clamp swung over and away from the unit or handset 24 to disconnect it from the base and to free the telephone for use.

While, as mentioned above, I prefer to construct the clamp of sheet-metal (as for example a strip of ribbon steel or the like) chromiumplated or otherwise finished to give a decorative and tarnish-resistant surface, it is also possible to employ other materials, such as synthetic resin (which can be molded or otherwise appropriately formed), etc.

The present invention may be embodied in other forms and, accordingly, the foregoin description is to be considered as illustrative and not restrictive, reference being made to the appended claims as indicative of the scope of the invention.

Having thus described my invention, I claim as new and desire to protect by Letters Patent:

1. For use with a French-type telephone having a handset and having a base equipped with a dial and an undercut shelf underlying the handset-rests; a locking-device comprising a clamp having an inturned engaging-lip at one end and having a lock at the other end, said engaging-lip being adapted to hook beneath the shelf with the 3 clamp overlying the handset, said lock being con-' structed and arranged releasably to engage with 4 the dial, thereby to prevent rotation of the dial and also to prevent lifting of the handset from the handset-rests.

2. A construction according to claim 1 wherein the clamp and the engaging-lip are integrally formed of sheet-metal or the like and wherein the clamp has a front-arm and a rear-arm together defining an acute angle and wherein the lock is constructed and arranged to engage within one of the finger-openings of the dial.

3. A construction according to claim 1 wherein the lock is provided with a boss and a lockingcam adapted to be fitted within one of the fingeropenings of the dial and wherein the locking-cam is constructed and arranged to be rotated to oilcenter position relative to said boss whereby it underlies the dial to one side of said finger-opening and prevents withdrawal of the look from said finger-opening.

JOHN STRAUCH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 749,388 Larned Jan. 12, 1904 1,454,768 Raymond May 8, 1923 1,596,176 Havland Aug. 17, 1926 2,292,206 Davis Aug. 4, 1942 

